1. Field of the Invention
The present invention relates to an improved high-capacity getter pump, suitable for creating and maintaining the vacuum, for instance in an ultra-high vacuum chamber or in a high-energy particle accelerator.
2. The Prior Art
Getter pumps are well known in the art and are suitable for creating and maintaining the vacuum. The first commercially successfull getter pump, described in U.S. Pat. No. 3,780,501, was employing, in a housing, a pleated metal strip having a getter metal embedded therein. Additional examples of such getter pumps were described in U.S. Pat. Nos. 3,609,064; 3,662,522; 3,961,897 and 4,137,012. Although these former getter pumps enjoyed a wide commercial success and market acceptance, they were still suffering from a drawback, residing in a limited sorption capacity inside a given volume.
In order to increase said sorption capacity, it was suggested to simply fill the pump housing with a getter material in the form of pellets, having size and shape similar to those (tablets) used in the field of drugs; such pellets were typically showing a cylindrical shape, with a diameter of 5-10 mm and a height of 2-10 mm. However, when the housing is filled with such pellets, the access of the gas to the bulky getter structure is far from being satisfactory. Another drawback, bound to the use of said pellets, was their tendency to produce undesired loose particles; moreover the bulky structure show safety problems because of the possibility of a high exothermicity of the getter material during possible ignitions (in particular when the used getter material has a low activation temperature).
Accordingly, it is a first object of the present invention to provide an improved getter pump substantially free from one or more of the drawbacks hereinabove.
Another object of the invention is to provide an improved getter pump having a higher sorption rate per unit volume, with respect to the getter pumps of the prior art.
A further object of the invention is to provide an improved getter pump having a higher sorption capacity per unit volume, with respect to the getter pumps of the prior art.
An additional object of the invention is to provide an improved getter pump resorting neither to pleated coated strips nor to pellets of getter material.
Other objects of the invention will be apparent to those of ordinary skill in the art, by reference to the following disclosure and drawings.